Walkers having integral seats are shown in several U.S. patents including U.S. Pat. Nos. 4,861,051, 4,623,163, 4,187,869, 4,046,374, 2,745,465, 2,374,182, 2,362,466, 2,129,260, 1,917,440 and 1,307,058. Among the above-listed patents, most of the disclosed seat assemblies are connected to the frame of the walker. Only two allow for vertical seat adjustment; U.S. Pat. Nos. 2,362,466 and 4,187,869, and neither of these two patents discloses seat arrangements which effectively assist the user in standing upright from the seated position.
In U.S. Pat. No. 4,187,869, a walker is disclosed having a vertically adjustable seat which is adjusted by rotating a vertically positioned lead screw to which the seat is indirectly engaged. Although this action causes the seat height to change, the seat is not intended to be raised or lowered while the user is sitting; therefore, this action does not help the user to stand up from the seat. Even if the this seat arrangement were intended to help the user stand upright, the turning of the lead screw is not automatic and would require much strength either from the seated user (which may be lacking) or an assistant.
The seat arrangement of the walker disclosed in U.S. Pat. No. 2,362,466 is hydraulically actuated by a hand pump mounted to the frame of the walker. This height adjustment of this seat is again not intended to help the user to an upright position. Like U.S. Pat. No. 4,187,869, the lifting action of the seat is neither automatic nor easily operated.
The various seat arrangements disclosed in the above-listed patents are not intended to be automatically moved away from the legs of the user while he or she is using the walker. The seat assemblies of these patents restrict the stride of the user and could cause the user to fall by interfering with his or her walking.
The following patents of those listed above disclose walking aid devices which have seat assemblies that are intended to be swung into an operational position (ready to support a seated person) and moved, if necessary and when not in use, from the legs of the user. U.S. Pat. No. 2,374,182 discloses an invalid walker having a frame which surrounds a user and supports him as he walks. The frame has an opening which allows the user access to within the frame. A seat may be swung from a stowed position located on the frame to a position lying across the opening. The seat when locked in its operative position allows the user to sit down and rest.
One problem with the seat disclosed in the '182 patent is that it must be moved to the operative position when the user wishes to sit. Depending on the condition of the user, he cannot be expected to operate the seat himself and an attempt to do so could cause the user to fall. Furthermore, the operative seat assembly is made so that it will not interfere with the legs of the user as he walks; however, the seat assembly has a relatively small supporting surface which may fail to retain an invalid in the seated position.
In the "walking" crutch disclosed by U.S. Pat. No. 1,917,440, a seat assembly is provided which may fold from a stowed position where it is away from the moving legs of the user to an operative position where the user my sit. Like the seat of U.S. Pat. No. 2,374,182, the seat of U.S. Pat. No. 1,917,440 must be moved to the operative position before the user sits. Also, the seat of U.S. Pat. No. 1,917,440 is made with a small supporting surface so that it may be swung down to its operative position without moving the user (or having the user move) away from the support of the frame of the crutch. This small supporting surface provides little support to the user's thighs, where it is needed to retain the user in the seat. It is likely that an invalid using the seat assembly of U.S. Pat. No. 1,917,440 would fall from it due to the lack of support under his thighs.
A similar seating assembly is shown in U.S. Pat. No. 2,362,466. Here, the seat again must be moved to an operative position from a stowed position and again, due to its size, will provide little support where it is needed by the user.
Certain walkers in the prior art have seats similar to bicycle seats, as shown by U.S. Pat. Nos. 4,187,869, 1,307,058 and 1,917,440. Although these seats, for the most part, may be permanently located in a supportive position with respect to the user without interfering with the walking action of the user, they provide very little support to keep an invalid seated and should he fall, the seat itself could cause injury.
Accordingly, it is an object of the invention to provide a walker having an integral seat assembly which automatically provides lifting assistance to a user to help the user stand upright from a seated position.
Another object of the invention is to provide an integral seat assembly for a walker which is automatically moveable between a stowed position, wherein the seat is away from the user's legs as he walks, and an operative position wherein the seat supports the user as he sits.
Another object of the invention is to provide such an automatically moveable seat assembly for a walker wherein the seat moves between its positions in response to the weight of the user as he sits.
Another object of the invention is to provide a seat assembly of which at least a portion automatically folds out of the way when it is not needed and automatically unfolds, when needed, to form a seat having a large supporting surface, yet not interfering with the walking action of the user.